Thanks sooty,I agree with your comments that the calcium soaps are too sticky to deal with.

Of course with my method I was simply using the CaO to dry the potassium methoxide and not directly as the catalyst. This part of the method worked very well and from Sandy Brae tests I did on the dried methoxide the water level was reduced by some 85% which was evident in the much lower amount of glycerol extracted from the process and higher yield.

As said the removal of the calcium soaps is difficult to say the least and the batch that just used the dried potassium methoxide had to be passed through woodchips three times to achieve a zero soap level.

Nothing ventured, nothing gained (as they say) with this in mind I will revert back to my catalyst mix of around 2/3 ASM and 1/3 KOH which seems to be the best combination for being as dry as possible and still yielding liquid glycerol.

Originally posted by Dgs:...which was evident in the much lower amount of glycerol extracted from the process and higher yield

I am making a wild guess that even though you did not mention it, you did a first stage glycerine "Pre-wash" reaction that contained an unknown quantity of methanol and Caustic and biodiesel which you have not included in the story you are telling us.

Two things come to mind:1. There is about 74ml glycerine per litre WVO reacted. That comes out to about 14.8litres Glycerine in 200 litres WVO.You say you produced 15 Litres glycerine from 200 litres WVO in your "12%" reaction.That means you have produced glycerine with a purity of about 98.67% purity during a one stage reaction.I find this very unlikely

If you did a first stage "glycerine Prewash" that you forgot to mention in your first post, when you drained the glycerine from the unmentioned first stage reaction, the glycerine produced in the first stage drained out with it.That explains why you had so little glycerine in your second stage "12%" reaction. Everyone knows the glycerine amount production is reduced in the second stage.

2. This also explains your claim of a yield of "104%".Everyone knows that biodiesel bound in the glycerine is released during a glycerine pre-wash and you end up with more "oil" in the reactor after the glycerine Pre-wash.The more glycerine used in the first stage the more biodiesel released into the reactor which is then included in the total amount of biodiesel produced.

Of course you might not have performed a first stage glycerine pre-wash that you forgot to mention and you have actually discovered a "magical" procedure that uses just 12% methoxide, produces glycerine with a purity of around 98.67% AND produces "over unity" amounts of biodiesel.But I doubt it.

Dgs,Thanks for the confirmation with a Sandy Brae that Quicklime will dehydrate Lye-Methanol preparations. I tried to dehydrate Lye-Methanol preps with both Garden Lime as well as microsieve but could not test for water using the home brew technique of a carbide manometer because the methanol and carbide seem to react thereby hugely increasing any result and using a Tralles hydrometer was anybody's guess.My desire in dehydrating the Lye/methanol is because I still get high soaps in my process, even though my oil is very dry and I titrate carefully. Passing bio through chips three times is common for me.

Originally posted by sooty:My desire in dehydrating the Lye/methanol is because I still get high soaps in my process, even though my oil is very dry and I titrate carefully. Passing bio through chips three times is common for me.Sooty

What does your WVO titrate?What type of production procedure are you using- Single stage, 2 stage, 2 stage with a first stage glycerine pre wash, etc etc.

Neutralizing the FFA's with NaOH or KOH produces soap and water.Even If you dry the methoxide you will still be producing soap and water directly when you neutralize the FFA's.

Of course the longer you allow the biodiesel to settle before "washing", the more soap that will settle to the bottom through gravity

Originally posted by RickDaTech:How does one get their hands on quicklime?

Rick

Quicklime CaO used to be sold at farmer's supply businesses as 'lime'. It was also sold at builder's suppliers as 'quicklime' for making mortar. However I've noticed that CaCO3 calcium carbonate is also sold as 'lime' so one has to read labels to be sure. Wear rubber gloves to avoid getting your hands on quicklime, it's caustic; wear a mask and goggles too.

sooty,yes indeed the carbide and methanol do react to form water so any method using calcium carbide will give a false high result.

I must say the lime drying process works really well, the amount of potassium soap formed seemed to be minimal the way it water washed, it's just the formation of the calcium soaps that are the problem.

As you use lye and not potassium the amount of CaO you need will be less, have you ever tried using it in a 1/1 ratio with the lye to hopefully produce less calcium methoxide.

Sometimes it takes a while to get ones head around these things. As you have used the woodchips with success I suppose you have got used to doing it.

My friend who has also been doing this trial has had his bio settling for the last 2 weeks and has just set up his woodchip bucket. He ran off about 1 1/2 litres today from the bottom of his 160 litre batch which was milky, presumably from the calcium soaps. He tested the soap in the batch using the 320 factor for potassium and got a level of 190ppm. However I think the correct factor for calcium soaps is something like 604, so it maybe closer to the 400ppm.

However, it looks as though the calcium soaps do settle with time, but how long they would take is unknown.

Originally posted by RickDaTech:I think I'm going to have to get me some quicklime and try this out.

Rick

Apparently it is a wonderful procedure.If I didn't know better, I would guess that this procedure would give much the same results as using sodium methylated. However, if you believe what some people claim, you need ONLY 12% methoxide for a 104% yield!!

I am not sure how removing the water produced making methoxide from KOH gives such miraculous results but there you go.I eagerly await the results of your experiments.

Tilly I love your writings, your accurate critical chemical analysis. The production of methoxide from caustic and methanol producing water as a byproduct is an equilibrium reaction. So by removing the water from the right side of the reaction pushes the reaction to the right, therefore a higher methoxide concentration. I did not do the calculations at this time, that takes a while, but producing more than 100% of product theoretically, on paper is correct. I do not disbelieve it.

Originally posted by sooty:My desire in dehydrating the Lye/methanol is because I still get high soaps in my process, even though my oil is very dry and I titrate carefully. Passing bio through chips three times is common for me.Sooty

What does your WVO titrate?What type of production procedure are you using- Single stage, 2 stage, 2 stage with a first stage glycerine pre wash, etc etc.Neutralizing the FFA's with NaOH or KOH produces soap and water.Even If you dry the methoxide you will still be producing soap and water directly when you neutralize the FFA's. Of course the longer you allow the biodiesel to settle before "washing", the more soap that will settle to the bottom through gravity

Tilly,I use a pre-treat with WBD glycerin, "no titration" method, sometimes needs 3 stages, air wash, settle then dry wash. Pretreat water is over 3000ppm, post-treat is 1300PPM and is then further venturi de-watered to less than 450ppm.I pretreat to remove water and junk. The WVO titrates at 1.1 before pretreatment and sometimes 0.8 after. I titrate because I want to confirm if no tit works and besides titration is fun.

Once pass 3/27 the 1st stage glycerin is returned and WBDemethed for whatever methanol % over 12.5% I used but always allowing 0.5 liter extra to remain. WBD Glycerin goes to a covered pretreatment barrel with next batch of heated WVO. Biodiesel then totally demethed and transferred to covered but vented soap settling tank and air bubbled for 6+ hours while hot ( I check % methanol exiting the tank with a breathalyzer), then allowed to settle for days.After soap settle, biodiesel cycled through red oak chips then sits in them for 1+ days, then transferred to storage as next batch comes.

So I guess I would be a: Pretreat, no tit, 2 stage with WBD, air and dry wash soap settle system. Or PNT2WBDAWDWSS for short.

After #5 20 gallon batches I will have 10 gallons of soap sludge in the bottom of my soap settling barrel. After 1 month of storage will have a few inches of soap in the bottom of 25 gallon storage barrel.

That 10% as soap could have been biodiesel. At 1.0 titration for FFAs might be as good as I can get (titration of 1 = 10% FFA and I got 10 gallons of soap form 100 gallons of biodiesel)BUT there is all that water in NaOH/Methanol mix and so my interest in a home brew Anhydrous Sodium Methoxide.

Hi sooty,I'm suprised your water level after pre-treat is so high. My oil also titrates at around the 1.1 level (KOH) and both KF and SB tests show after a settling period the water is in the 8 to 900ppm range. After pre-treat the water is in the 350ppm range.

I'm also suprised that after your pre-treat your oil still titrates so high. When you are striving to reduce the water in the methoxide it is important to have no titration from your oil before the methoxide is added. If you add a very small amount of your dry methoxide to the pre-treat glycerol you will be able to achieve this.

As the ffa neutralisation is taking place in the presence of glycerol then most of the water from this reaction will be absorbed into the glycerol. This results in having your oil acting 'as new' when you add your methoxide.

Having said that, a titration of 1.0 will only yield about 320ppm water, insignificant to the 320gms of water that will be formed for every 1000gms of NaOH used.

WesleyB, hello.From our chemists on the UK VOD I am led to believe that depending on the mix and type of fatty acids an average of around 105 litres of finished biodiesel should be achieved from an anhydrous process, from 100 litres of vegetable oil.

That is certainly a lot of "processing"Have you compared the benefits of using this method to a single stage procedure with titration?

I assume you are able to use less total chemicals, however because you are using a titrationless procedure, just guessing at the amount of Caustic to use in the first stage is likely to result in some "unused" methanol remaining in the first stage that goes out when you drain the first stage glycerine.

On average, what percent methanol would you use in the first stage and what percent methanol would you use in the second stage?

The production of methoxide from caustic and methanol producing water as a byproduct is an equilibrium reaction. So by removing the water from the right side of the reaction pushes the reaction to the right, therefore a higher methoxide concentration.

Do you think that the reaction is pushed so far to the right that the reaction producing the biodiesel is no longer an equilibrium reaction and in fact does not even require a Stoicheometric amount of methanol?Have you actually ever performed any testing that demonstrates that all that is required is 12% methanol?

quote:

I did not do the calculations at this time, that takes a while, but producing more than 100% of product theoretically, on paper is correct. I do not disbelieve it.

Indeed it is correct.The chemist Neutral gave it as around 103.5% V/V.Of course that is with unused oil with 0 FFA under laboratory conditions.In the 15 years I have been making biodiesel I can not recall anyone claiming even 100% yield for their standard production procedure let alone using less than stoichiometric methanol

The question is, has a yield of 104% using Just 12% methanol that passes Warnqvest really been Achieved?As Dr Phill often says: ""The best predictor of future behavior is relevant past behavior"In the past, when he has made these amazing claims it has turned out that some reaction steps/ chemicals had been left out of the description such as a first stage Glycerine pre- wash containing additional methoxide and residual biodiesel.

I seriously doubt that a yield of 104% using only 12% methoxide in the reaction with WVO titrating around 1 KOH is possible.However, if you want to go back into your lab and do some tests around these peramaters and you can achieve the same results, please let us know.

Hey Guys, I think some of you may be missing one of the main advantages of using sodium/potassium methoxide. That is, it chemically reacts with not only water in the oil, but also the water generated by neutralizing the acids.

Originally posted by RickDaTech:Hey Guys, I think some of you may be missing one of the main advantages of using sodium/potassium methoxide. That is, it chemically reacts with not only water in the oil, but also the water generated by neutralizing the acids.

Can you explain what you mean.As far as I am aware, most of us use either Sodium or potassium methoxide in the reaction.Most of us mix either NaOH or KOH into methanol to produce the methoxide.

The extra step in this method only removes the slight amount of water produced when mixing the potassium or the NaOH with the Methanol. That is ALL it does. It does not produce extra biodiesel from the water. It does not convert the FFA's into biodiesel.This extra procedure has nothing to do with the water produced when Neutralizing the FFA's.

quote:

Something similar may be happening here.

I think the thing that is happening here is that he has failed to mention his first stage glycerine pre-wash and has not taken into account the chemicals and biodiesel contained in the glycerine when he claims to have achieved a 104% yield using 12% methoxide.

The methoxide drying stage removes the water produced when either KOH or NaOH is dissolved in methanol.

This amount of water is considerable. If 1.4kgs of KOH were dissolved into 20 litres of anhydrous methanol the water produced would be 448gms which amounts to about 2.16% (the resultant mix will be about 20.7 litres total volume)

2.16% is not a slight amount, it has massive implications for soap production.

This message has been edited. Last edited by: Dgs, February 01, 2016 01:35 PM

Hi Dgs,This is all well and good, but I would like to get back to the magical part of your post when you claimed that you used less than a stoiochemetric amount of Methanol to perform an equilibrium reaction- about 12%There is also the concern that if we are to believe that you actually only made 15 litres of byproduct for the full reaction, that would mean that the byproduct consisted of about 98% purity glycerine.

Now while I think you may have convinced WesleyB that you have actually done this, I am always skeptical about a procedure that requires a magic step to achieve.

"The best predictor of future behavior is relevant past behavior."- Dr. Phil

In the past, when you have made these amazing claims of using less than Stoicheometric amounts of Methanol to perform a reaction, under closer questioning it has turned out that you did a glycerine pre-wash that you did not mention.I am sure that in this latest case you have also performed a pre-wash that you did not mention when describing what you did.I just can not understand why you seem to be so hesitant to mention glycerine prewashes when you describe your production procedures. The glycerine contains methoxide and biodiesel and has a very real affect on the reaction.And then it does not require a magic step to explain what you have done.